${\sqrt{16} = \text{?}}$
$\sqrt{16}$ is the number that, when multiplied by itself, equals $16$ If you can't think of that number, you can break down $16$ into its prime factorization and look for equal groups of numbers. So the prime factorization of $16$ is $2\times 2\times 2\times 2$ We're looking for $\sqrt{16}$ , so we want to split the prime factors into two identical groups. Notice that we can rearrange the factors like so: $16 = 2 \times 2 \times 2 \times 2 = \left(2\times 2\right) \times \left(2 \times 2\right)$ So $\left(2\times 2\right)^2 = 4^2 = 16$ So $\sqrt{16}$ is $4$.